Inverters

siegfried

I have bought an inverter to charge our new laptop & camcorder - we tried keeping a camcorder going for four weeks without hookup last Autumn & it wasn't easy. Having studied the old postings, it seems that trying to charge a toothbrush brings grief & a big bill. Are there any other problems?

It has been suggested on other forums that the item to be charged should be switched on before connecting to the inverter. It has even been sugggested that the inverter should not be switched on with the engine running, which would appear to negate much of its value, particularly to those who use a laptop navigation system.

Any help much appreciated.

Siegfried

autostratus · Moderator

Hi

We have an inverter and without having this forum to refer to, killed our toothbrush charger. We have since then also killed the charger for our camera rechargeables.
While we discovered that it is the indirect charging that's affected we didn't realise the rechargeable battery charger was such as we had used another battery charger without problems.

You mention switching on with the engine running.
I haven't got the instruction book to hand but I thought that the caution was not to have the inverter plugged in when starting the engine. I assume this is because of the surge when the engine is started which settles down when running.
We always plug our inverter in after the engine is started. After we move off we switch it on to power the accessories.

GeorgeTelford

Hi Siegfried

The toothbrush problem is with Modified (or Quasi) Sine wave invertors, if you buy a pure sine wave invertor (so if the one you have bought is pure no probs)

Use the socket on the invertor like a normal wall socket, plug in the item then switch on.

I have not seen any valid reason posted anywhere for not using an invertor with the engine running. I use one of mine with engine running all the time now for sat nav no problems at all.

There is however one situation where it is not a good idea. Say you are using a Large invertor to run a microwave or other large wattage item.

If the invertor is run by leisure battery and you come to use the invertor and find the leisure battery is low, there is a temptation to run the engine.

But this would try to draw most of the current via the split charge relay, at best this would blow the split charging system relay (if there is a fuse fitted on several occassions I have come across systems with no fuse fitted, with no fuse its a serious fire hazard)

George

brianwatson

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now supply a DC to DC adapter for laptops. It has an adjustable voltage range from about 9volts to 24 volts. I have used one for several months and had no problems.

My navigation software is on the laptop and it works for several hours whilst you are driving around and the laptop thinks it is on AC power. It will even charge up the laptop battery as well.

Anonymous

I used my inverter to charge my laptop but eventually the laptop batteries packed up. Although I can't be sure reading this & other newsgroups it could be due to the inverter (it was one of the cheaper type & that also eventually died). I have read that some electonic equipment either will not work or can be damaged using the modified sine wave type. I now run my laptop using a Kerio 12 volt laptop adapter from Maplins, the output is up to 20volts.

Anonymous

[quote:ce0cb48a27="GeorgeTelford"]

But this would try to draw most of the current via the split charge relay, at best this would blow the split charging system relay (if there is a fuse fitted on several occassions I have come across systems with no fuse fitted, with no fuse its a serious fire hazard)

George[/quote:ce0cb48a27]

Surely this is a case where the relay is not the correct size, ALL of the charging system SHOULD be capable of carrying the maximum output from the alternator or the charger.

I run a 2000 watt inverter and when I have somthing big to do ie microwave or power tools I run the engine, not to do so would soon drain my batterys.

Doug..

GeorgeTelford

Hi Doug

Worst case

You Invertor 2000W is probably capable of 3000W Surge thats 250 Amps at 12v.

Have you got a 250 Amp relay?

You maybe thinking my alternator is only 90Amps, but dont forget the Starter battery, this is easily capable of supplying 250 A

Yes the system should be set up to carry the maximum current but it very rarely is.

There is no problems if your leisure battery is not run down, but if the leisure was a little low..........

George

lecky7

would somebody tell the difference between modified & pure sine wave inverters, which are the best one to get, I suppose it depends on what you want to use it for. I know one is a lot more expensive than the other

rednev

HI at present i charge my camcorder from the cig lighter 12v socket when we are driving along with a suitable cable supplied from hi/fi shop saves a lot of problems when we do not use hook ups ie wild camping,Paul.

PamNPete

You may see 250A on the meter when starting, this is only for a short period and would sson drain the battery if it were constant - because the battery is capable of giving out this current over a short period - a smaller engine would take less - OK

The 90A Alternator would be capable of chargng this battery - It doesnt have to be charged at 250A - in fact if this 250A were to be supplied to charge you could end up with buckled plates

To get back to when the the Invertet should be connected to the engine

During starting the voltage at the 12V output will vary widely from high values to a possible negative - who knows I doubt that any one who has replied has the necessary equipment to measure it _ I certainly havent now - I did have when I worked.

Once the engine is running. That is the correct time to connect in the inverter
I always connect up the equipment to the charger before switching the charger on, mainly to preserve the contacts on the equipment
Similarly I switch off the charger before unplugging the equipment and un plugging the charger from its supply